IMPORTANCE: Although millions of transfusions are given annually worldwide, the effect of red blood cell (RBC) unit storage duration on oxygen delivery is uncertain.

OBJECTIVE: To determine if longer-storage RBC units are not inferior to shorter-storage RBC units for tissue oxygenation as measured by reduction in blood lactate levels and improvement in cerebral tissue oxygen saturation among children with severe anemia.

DESIGN, SETTING, AND PARTICIPANTS: Randomized noninferiority trial of 290 children (aged 6-60 months), most with malaria or sickle cell disease, presenting February 2013 through May 2015 to a university-affiliated national referral hospital in Kampala, Uganda, with a hemoglobin level of 5 g/dL or lower and a lactate level of 5 mmol/L or higher.

INTERVENTIONS: Patients were randomly assigned to receive RBC units stored 25 to 35 days (longer-storage group; n = 145) vs 1 to 10 days (shorter-storage group; n = 145). All units were leukoreduced prior to storage. All patients received 10 mL/kg of RBCs during hours 0 through 2 and, if indicated per protocol, an additional 10 mL/kg during hours 4 through 6.

MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of patients with a lactate level of 3 mmol/L or lower at 8 hours using a margin of noninferiority equal to an absolute difference of 25%. Secondary measures included noninvasive cerebral tissue oxygen saturation during the first transfusion, clinical and laboratory changes up to 24 hours, and survival and health at 30 days after transfusion. Adverse events were monitored up to 24 hours.

RESULTS: In the total population of 290 children, the mean (SD) presenting hemoglobin level was 3.7 g/dL (1.3) and mean lactate level was 9.3 mmol/L (3.4). Median (interquartile range) RBC unit storage was 8 days (7-9) for shorter storage vs 32 days (30-34) for longer storage without overlap. The proportion achieving the primary end point was 0.61 (95% CI, 0.52 to 0.69) in the longer-storage group vs 0.58 (95% CI, 0.49 to 0.66) in the shorter-storage group (between-group difference, 0.03 [95% CI, -0.07 to ∞], P < .001), meeting the prespecified margin of noninferiority. Mean lactate levels were not statistically different between the 2 groups at 0, 2, 4, 6, 8, or 24 hours. Kaplan-Meier analysis and global nonlinear regression revealed no statistical difference in lactate reduction between the 2 groups. Clinical assessment, cerebral oxygen saturation, electrolyte abnormalities, adverse events, survival, and 30-day recovery were also not significantly different between the groups.

CONCLUSIONS AND RELEVANCE: Among children with lactic acidosis due to severe anemia, transfusion of longer-storage compared with shorter-storage RBC units did not result in inferior reduction of elevated blood lactate levels. These findings have relevance regarding the efficacy of stored RBC transfusion for patients with critical tissue hypoxia and lactic acidosis due to anemia.

INTERVENTIONS: Patients were randomized to undergo either high-flow or conventional oxygen therapy for 24 hours after extubation.

MAIN OUTCOMES AND MEASURES: The primary outcome was reintubation within 72 hours, compared with the Cochran-Mantel-Haenszel χ2 test. Secondary outcomes included postextubation respiratory failure, respiratory infection, sepsis and multiorgan failure, ICU and hospital length of stay and mortality, adverse events, and time to reintubation.

CONCLUSIONS AND RELEVANCE: Among extubated patients at low risk for reintubation, the use of high-flow nasal cannula oxygen compared with conventional oxygen therapy reduced the risk of reintubation within 72 hours.

DESIGN, SETTING, AND PARTICIPANTS: The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation, conducted during 4 consecutive weeks in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across 5 continents.

EXPOSURES: Acute respiratory distress syndrome.

MAIN OUTCOMES AND MEASURES: The primary outcome was ICU incidence of ARDS. Secondary outcomes included assessment of clinician recognition of ARDS, the application of ventilatory management, the use of adjunctive interventions in routine clinical practice, and clinical outcomes from ARDS.

RESULTS: Of 29,144 patients admitted to participating ICUs, 3022 (10.4%) fulfilled ARDS criteria. Of these, 2377 patients developed ARDS in the first 48 hours and whose respiratory failure was managed with invasive mechanical ventilation. The period prevalence of mild ARDS was 30.0% (95% CI, 28.2%-31.9%); of moderate ARDS, 46.6% (95% CI, 44.5%-48.6%); and of severe ARDS, 23.4% (95% CI, 21.7%-25.2%). ARDS represented 0.42 cases per ICU bed over 4 weeks and represented 10.4% (95% CI, 10.0%-10.7%) of ICU admissions and 23.4% of patients requiring mechanical ventilation. Clinical recognition of ARDS ranged from 51.3% (95% CI, 47.5%-55.0%) in mild to 78.5% (95% CI, 74.8%-81.8%) in severe ARDS. Less than two-thirds of patients with ARDS received a tidal volume 8 of mL/kg or less of predicted body weight. Plateau pressure was measured in 40.1% (95% CI, 38.2-42.1), whereas 82.6% (95% CI, 81.0%-84.1%) received a positive end-expository pressure (PEEP) of less than 12 cm H2O. Prone positioning was used in 16.3% (95% CI, 13.7%-19.2%) of patients with severe ARDS. Clinician recognition of ARDS was associated with higher PEEP, greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9% (95% CI, 31.4%-38.5%) for those with mild, 40.3% (95% CI, 37.4%-43.3%) for those with moderate, and 46.1% (95% CI, 41.9%-50.4%) for those with severe ARDS.

CONCLUSIONS AND RELEVANCE: Among ICUs in 50 countries, the period prevalence of ARDS was 10.4% of ICU admissions. This syndrome appeared to be underrecognized and undertreated and associated with a high mortality rate. These findings indicate the potential for improvement in the management of patients with ARDS.

IMPORTANCE: Noninvasive ventilation has been recommended to decrease mortality among immunocompromised patients with hypoxemic acute respiratory failure. However, its effectiveness for this indication remains unclear.

MAIN OUTCOMES AND MEASURES: The primary outcome was day-28 mortality. Secondary outcomes were intubation, Sequential Organ Failure Assessment score on day 3, ICU-acquired infections, duration of mechanical ventilation, and ICU length of stay.

RESULTS: At randomization, median oxygen flow was 9 L/min (interquartile range, 5-15) in the noninvasive ventilation group and 9 L/min (interquartile range, 6-15) in the oxygen group. All patients in the noninvasive ventilation group received the first noninvasive ventilation session immediately after randomization. On day 28 after randomization, 46 deaths (24.1%) had occurred in the noninvasive ventilation group vs 50 (27.3%) in the oxygen group (absolute difference, -3.2 [95% CI, -12.1 to 5.6]; P = .47). Oxygenation failure occurred in 155 patients overall (41.4%), 73 (38.2%) in the noninvasive ventilation group and 82 (44.8%) in the oxygen group (absolute difference, -6.6 [95% CI, -16.6 to 3.4]; P = .20). There were no significant differences in ICU-acquired infections, duration of mechanical ventilation, or lengths of ICU or hospital stays.

CONCLUSIONS AND RELEVANCE: Among immunocompromised patients admitted to the ICU with hypoxemic acute respiratory failure, early noninvasive ventilation compared with oxygen therapy alone did not reduce 28-day mortality. However, study power was limited.